The Canon 16-35mm f/4L IS USM is a pro and prosumer-oriented lens for full-frame Canon DSLRs, such as the Canon 5D Mark III, designed for photojounalism, weddings, architecture and nature photography, and is built ruggedly so it can be used in a variety of shooting conditions. While its focal range is very close to the 17-40mm f/4L, as a 16-35mm its focal range aligns precisely with the existing and faster 16-35mm f/2.8 II and it is compatible with full-frame cameras.

Although it offers a smaller continuous f/4 maximum aperture, it more than makes up for it with the addition of Image Stabilization, which Canon claims extends its hand-holdability in low light by four stops. The smaller aperture allso allows the lens to be smaller and lighter, measuring 3.3x4.4 inches and weighing in at 21.7 ounces—smaller and lighter than its f/2.8 counterpart. The aperture consists of 9 circular blades for pleasing bokeh, and focusing is internal. The lens has a minimum focus distance of 0.92 feet, and is dust- and water-resistant.

Canon EF-S 10-18mm f/4.5-5.6 IS STM

Canon today also announced a super-wide lens for its APS-C sensor DSLRs such as the EOS Rebel SL1, the Canon EF-S 10-18mm f/4.5-5.6 IS STM. The new lens is designed for enthusiasts who want a lens that will take in a super-wide angle of view for travel and everyday photography as well as for video; its widest setting is equivalent to a 16mm lens on a 35mm camera.

Unlike the older and longer-ranging Canon EF-S 10-22mm f/3.5-4.5, the 10-18mm is smaller and lighter thanks to the smaller aperture. However, while it's a slower lens, as with the 16-35mm model it more than makes up for its smaller aperture by having Image Stabilization built-in. Canon claims a 4-stop handheld advantage of the 10-18mm over its predecessor.

The new lens has 14 elements in 11 groups and a circular 7-blade aperture for pleasing Bokeh. A Stepping Motor (STM) is said to be quick and quiet. The lens measures 2.9x2.8 inches and weighs 8.5 ounces, which is 5 ounces lighter than the 10-22mm lens.